Typical devices used to reduce available energy from an arc flash event, over-current event or arc fault will short out the electrical circuit while waiting for an upstream circuit to open and isolate the circuit. During this delay, considerable damage can be done by the energy being dissipated from the event that triggered the short.
When multiple feeder circuits are supplied with power from a common supply bus, circuit breakers are typically provided in each of the feeder circuits in addition to the main circuit breaker in the common supply bus. If the main circuit breaker trips before the circuit breaker of the feeder circuit in which the fault occurred, power can be unnecessarily lost in even the feeder circuits that were not affected by the fault condition.